hugetlb: support boot allocate different sizes

Make some infrastructure changes to allow boot-time allocation of
different hugepage page sizes.

- move all basic hstate initialisation into hugetlb_add_hstate
- create a new function hugetlb_hstate_alloc_pages() to do the
  actual initial page allocations. Call this function early in
  order to allocate giant pages from bootmem.
- Check for multiple hugepages= parameters

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Andrew Hastings <abh@cray.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 30 insertions, 9 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1a6fe87555b2..243a8684d180 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -981,15 +981,10 @@ static void __init gather_bootmem_prealloc(void)
         }
 }
 
-static void __init hugetlb_init_one_hstate(struct hstate *h)
+static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
 {
         unsigned long i;
 
-        for (i = 0; i < MAX_NUMNODES; ++i)
-                INIT_LIST_HEAD(&h->hugepage_freelists[i]);
-
-        h->hugetlb_next_nid = first_node(node_online_map);
-
         for (i = 0; i < h->max_huge_pages; ++i) {
                 if (h->order >= MAX_ORDER) {
                         if (!alloc_bootmem_huge_page(h))
@@ -997,7 +992,7 @@ static void __init hugetlb_init_one_hstate(struct hstate *h)
                 } else if (!alloc_fresh_huge_page(h))
                         break;
         }
-        h->max_huge_pages = h->free_huge_pages = h->nr_huge_pages = i;
+        h->max_huge_pages = i;
 }
 
 static void __init hugetlb_init_hstates(void)
@@ -1005,7 +1000,9 @@ static void __init hugetlb_init_hstates(void)
         struct hstate *h;
 
         for_each_hstate(h) {
-                hugetlb_init_one_hstate(h);
+                /* oversize hugepages were init'ed in early boot */
+                if (h->order < MAX_ORDER)
+                        hugetlb_hstate_alloc_pages(h);
         }
 }
 
@@ -1301,6 +1298,8 @@ module_init(hugetlb_init);
 void __init hugetlb_add_hstate(unsigned order)
 {
         struct hstate *h;
+        unsigned long i;
+
         if (size_to_hstate(PAGE_SIZE << order)) {
                 printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
                 return;
@@ -1310,15 +1309,21 @@ void __init hugetlb_add_hstate(unsigned order)
         h = &hstates[max_hstate++];
         h->order = order;
         h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
+        h->nr_huge_pages = 0;
+        h->free_huge_pages = 0;
+        for (i = 0; i < MAX_NUMNODES; ++i)
+                INIT_LIST_HEAD(&h->hugepage_freelists[i]);
+        h->hugetlb_next_nid = first_node(node_online_map);
         snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
                                         huge_page_size(h)/1024);
-        hugetlb_init_one_hstate(h);
+
         parsed_hstate = h;
 }
 
 static int __init hugetlb_setup(char *s)
 {
         unsigned long *mhp;
+        static unsigned long *last_mhp;
 
         /*
          * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
@@ -1329,9 +1334,25 @@ static int __init hugetlb_setup(char *s)
         else
                 mhp = &parsed_hstate->max_huge_pages;
 
+        if (mhp == last_mhp) {
+                printk(KERN_WARNING "hugepages= specified twice without "
+                        "interleaving hugepagesz=, ignoring\n");
+                return 1;
+        }
+
         if (sscanf(s, "%lu", mhp) <= 0)
                 *mhp = 0;
 
+        /*
+         * Global state is always initialized later in hugetlb_init.
+         * But we need to allocate >= MAX_ORDER hstates here early to still
+         * use the bootmem allocator.
+         */
+        if (max_hstate && parsed_hstate->order >= MAX_ORDER)
+                hugetlb_hstate_alloc_pages(parsed_hstate);
+
+        last_mhp = mhp;
+
         return 1;
 }
 __setup("hugepages=", hugetlb_setup);